If you look at the back of Mojo's chair, you can see an unhappy Jack Ball antenna topper. The happy smiley kind are given/sold by Jack-In-The-Box hamburger joints. In the final comic, it is covered up by a huge text balloon, as I bet the artist figured. If you look closely at Mojo at the bottom of the page and on other pages of the comic, you can still see it in silhouette sometimes, but never close enough to make them sue.